I am always hopeful that something like this might kill cryptocurrency (although I don't believe it will) - if a critical mass lose confidence in it, the network effect would collapse and people might stop wasting terawatt-hours of power on NFTs and exit scams.

Unlikely. The digital signatures bitcoin uses are regarded as secure, (there could be attacks if we get quantum computers.) The issue here was the software didn't put in enough randomness when generating the keys, and so it was straight forward to search the small space of keys the wallet would generate.

It's not so different if you encrypted a file with a weak password and someone guessed it—you don't need stronger encryption, you need to pick a better password.

The proof of work part of bitcoin is really for "consensus", so everyone agrees which transactions happened in which order, this attack didn't affect that part at all.

Need more GPUs.